Continuity mistake: A montage scene of newspaper headlines early on has March 12, 1939 as the date. Much later in the film, Jude Law asks Gwyneth Paltrow the date so he can calculate the position of a star. She responds "March 2" but there is absolutely nothing to indicate that nearly a year has passed.
Continuity mistake: When Joseph and Polly enter the Ark, we see the door close behind them, the countdown coming to zero. The Mysterious Woman, at the time, is out cold, or at least a dozen meters behind them. Yet, she finds her way onboard the Ark somehow.
Continuity mistake: When the robots invade New York City and are advancing on Polly in the street, the camera pans down to the robots' stomping feet. There is nothing there but open space for them to tromp on. The camera pans back to Polly taking a picture, then back to the robots' feet. Suddenly, a car has magically appeared in the path of the stomping robots and gets kicked towards her. (00:12:15)
Continuity mistake: When Polly stands up while Joe is attacking the robots, she is on the corner of a sidewalk. A few shots later, when Joe flies over her and she says "Joe", she is at a different place on the sidewalk. She was walking really slowly, so it's impossible that she moved that fast.
Continuity mistake: When the robots are going to capture Dex, the amount of debris and papers around him changes in each shot.
Continuity mistake: Polly meets Dr Jennings at the Radio City Music Hall at 6 pm but when she talks to Sky Captain later, she says that she met him in the morning.
Continuity mistake: On Totenkopf's rocket, Joe runs to cross the bridge, but Polly looks at the control panel behind her and pushes a button. Even if a few seconds have passed, Joe is still next to her.
Continuity mistake: When the scientist is killed by the electric device in front of Totenkopf's office, he is transformed in to ashes and bones but in the following shot, there are only bones on the floor.
Continuity mistake: On the airplane, Joe draws a line on the map to see where they will crash. The line changes place in each following shot.
Continuity mistake: In Sky captain's office, when he agrees that Polly travels with him, his head swaps positions depending if it's a front or back angle.
Continuity mistake: In front of Totenkopf's office, Joe shoots the robot with the metal melting gun, then push it on the ground. When the robot falls, it breaks the electric device that killed the scientist but in each following shot, the device is not broken. (01:23:15)
Continuity mistake: When Sky Captain and Polly go visit Dr. Jennings, it is pouring down rain, but when they enter his basement laboratory both of them are completely dry. Granted, they were only exposed to the rain for a few seconds in the distance from the car to the building, but they would still have gotten least a little wet.
Continuity mistake: When Joe and Polly are running on the tree trunk, Joe loses his gun but it is a completely different one when we see it falling.
Answer: None.
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